Diabetes mellitus (DM) is a chronic progressive lifelong disease, which is caused by body's metabolic disorder of carbohydrate, protein and lipid with characteristical manifestations of hyperglycemia and glycosuria. It can lead to complications of heart and kidney, blindness and even amputation. Recently, clinical studies showed that morbidity of DM has been rising year by year. By now, the number of patient with DM has amounted to 1.5-hundred millions all over the world. In China, the number of patient with DM has been over 40 millions. In DM cases, most of the patients belong to non-insulin-dependent diabetes mellitus (NIDDM, Type II), and a little belong to insulin-dependent DM (Type I). Thus, most of DM patients need medicine lifelong.
Now, treatment for DM is still dominated by chemical drugs, such as the sulfonamides, biguanide drugs, glucosidase inhibitor, glinides and insulin sensitizer etc. However, long-term use of these drugs will bring about severe side effects.
Traditional Chinese medicine (TCM) has a long history in prevention and treatment of DM. After thousand years of practice, much precious experience has been accumulated and the unique academic system has been established. A lot of glucose-reducing TCMs have been recorded in the TCM classics, for example Rhizoma Alismatis (Zexie), Rhizoma Anemarrhenae (Zhimu), Radix panacis quinquefolii (Xiyangshen), Radix Puerariae Lobatae (Gegen), Radix Rehmanniae (Dihuang) and pollen grain (Huafen) etc. Traditionally, treating DM by TCM is based on clinical symptoms according to “Sanxiao” theory, but has no good therapeutic method in the stage of impaired-glucose-tolerance and early stage of DM.
The main cause of DM is liver and stomach, and the existence of gloomy heat in body is the pathogenesis basis for “Xiaoke” disease (TCM name of DM). In light of the TCM theory of relieving liver depression and removing spleen dampness, it is necessary to adopt the method of regulation as the primary measurement, which is considered as a therapeutic way aiming at pathogenesis. Tangminling (the Chinese name of the pharmaceutical composition of the present invention) acts as relieving stagnancy to clear away stomach-heat, nourishing Yin to remove fire and dredging Fu to purge turbidity. It addresses both the symptoms and root cause. Since the gloomy heat has been eliminated, Qi and Yin will be recovered automatically. As elaborated in Xiaodan fascicule of Zheng Zhi Zhun Sheng (a great work written by Wang Ken Tang in Ming dynasty), an open way and vigorous body fluid could render Qi and blood suited for each other, and disease self-recovered. Accordingly, the therapeutic method of DM is to relieve stagnancy to clear away stomach-heat, nourish Yin to remove fire and dredge Fu to purge turbidity.
According to traditional TCM theory, the gastrointestinal stagnancy caused by overeating and reduced exercise usually checks transportation of Qi in “Zhongjiao” (middle warmer), which results in the closedown of dredging function of liver and gall. Stasis is converted into heat, the heat of “Sanjiao” (triple warmer) present in the organs of liver, gall, stomach, intestine and lung. Therefore, Rhizoma Coptidis and Radix et Rhizoma Rhei are used as the monarch drug, in which the Rhizoma Coptidis plays a part of clearing up stomach heat and Radix et Rhizoma Rhei dredging intestinal heat based on the theory of treating sweet by bitter. Radix Paeoniae Alba, Radix Scutellariae and Radix Bupleuri are used as the minister drug, where the Radix Paeoniae Alba plays a part of nourishing liver and astringing Yin, assisting the monarch drugs to clear up the heat in “Sanjiao” without damaging Yin; the Radix Bupleuri going into Shaoyang gall meridian and Jueyin liver meridian to clear up the heat of liver and gall and dredging spleen and stomach; the Radix Scutellariae clearing up the heat of lung and liver. The Fructus Aurantii Immaturus and raw Fructus Crataegi act as regulating Qi, digesting food and dispersing stasis, working with the Radix et Rhizoma Rhei to facilitate stomach and intestine; the Rhizoma Pinelliae with the Rhizoma Coptidis to render acrid opening and bitter downbearing to open middle warmer. Therefore, all of three drugs are used as assistant drug. The Fructus Mume acts as astringing Yin to regenerate body fluid based on the theory of treating sweet by acidity, working with the Radix Trichosanthis to make stomach's Yin vigorous. So it should be called as guide drug.
Based on the TCM theory of Gloomy Heat, a pharmaceutical composition has been found, which is composed of Radix Trichosanthis (Tianhuafen), Radix Bupleuri (Chaihu), Fructus Aurantii Immaturus (Zhishi), Radix et Rhizoma Rhei (Dahuang), Rhizoma Pinelliae (Banxia), Radix Scutellariae (Huangqin), Rhizoma Coptidis (Huanglian), Radix Paeoniae Alba (Baishao) and Fructus Mume (Wumei) etc. It has a better efficacy on treating DM. The composition has been disclosed in an early Chinese patent application by the applicant (No. 200410020220.7). However, the method used was based on the traditional ethanol-extraction method. Due to limitations in chemical property of solvent, a large amount of water-soluble active components are lost in the extract obtained by this method. Both the yields and the contents of the active components of the extract are low. Thus, the administration dosage is high, and consequently the side-effects are increased correspondingly.